400 turbo to either 350turbo or 700r4
 

What would I need to do to convert from a 400 turbo to either a 350 turbo or a 700r4?

Thanks

different driveshaft different yoke on the driveshaft. if you swap to a th350 you can use the torque convertor from the th400. the 700r4 needs a few extras. why are you swapping i know you had problems with the builder on that th400 but i would never downgrade like that. the th400 is twice as strong as both of those trannies

Not swapping yet. But if he cant get the 400 going and offers up the 700 I am goingto take it. I want the overdrive :) As far as tranny strength goes it is a stock engine. So if it can handle that I wil be happy and on a side note I can put my 3.73 rear back in :)

oh ok you should be fine either way then. personally i would keep the th400 as most know i totally dislike 700r4's. tearing the seal going on the drum putting it into the case happens and isnt usually noticeable when ya do it putting a unit together. im betting your problem will be fixed when they put a paper and rubber kit in your tranny